1. Field of the Invention
The present invention relates to a data transmission system, a data recording and reproducing apparatus, and a recording medium each having a data structure of error correcting code, a data structure for use in a recording medium, a method for arranging a parity of an error correction code, a method for transmitting information data, a method for receiving information data, a method for recording information data in a recording medium, and a method for reproducing information data from a recording medium.
In particular, the present invention relates to a data transmission system for transmitting data through a communication line, a data recording and reproducing apparatus for recording data into a recording medium and reproducing data from the recording medium, and a recording medium such as an optical disk, a magneto-optical disk, a magnetic disk, a compact disk, a magnetic tape, a semiconductor memory, or the like, each of the data transmission system, the data recording and reproducing apparatus, and the recording medium having a data structure of error correcting code, a data structure for use in a recording medium, a method for arranging a parity of an error correcting code, a method for transmitting information data, a method for receiving information data, a method for recording information data in a recording medium, and a method for reproducing information data from a recording medium.
2. Description of the Prior Art
When transmitting and recording a great amount of digital data, an error correcting code (referred to as an ECC hereinafter) is widely used for the purpose of improving the reliability of the data.
The ECC word generated by attaching a parity to an original data, and then, the redundancy of the data having the parity increases, however, the ECC has the capabilities of detecting and correcting errors generated in the process of transmitting, recording and reproducing the data.
In general, the ECC has a higher error correcting capability when the ECC word has an increased redundancy, i.e., when the ECC word includes a greater amount of parity symbols. Therefore, the ECC word includes a plurality of parity symbols or bytes.
Conventionally, when ECC encoding a great amount of data upon transmitting or recording the data, the data is previously divided into a plurality of blocks each having a predetermined length, and a parity is attached to each block. Then, the parity is arranged at the tail of the block to be corrected, generally. That is, in the conventional process of data transmission, the data has been transmitted with the parity added to the tail of each data block. On the other hand, in the data recording process, the parity has been recorded in a position adjacent to each data block.
An arrangement of the data and the parity of the ECC word in the conventional data recording method is concretely shown in FIG. 1.
FIG. 1 shows a logical data format of one block of an optical disk in which data and a parity are recorded by a prior art method for arranging the parity of the ECC.
The block is divided into a data area 90, a row parity area 54, and a column parity area 53, depending on the type of information data recorded. In the present case, the parity is a part of the ECC word. As is apparent from FIG. 1, the row parity area 54 and the column parity area 53 are partially overlapped with each other.
One block is comprised of 156 data frames 51 and 12 parity frames. In the present case, the frame 51 means a group of data or parities corresponding to one row of each block, and constructs an ECC word in the row direction.
Each data frame 51 is comprised of data of 158 bytes and a row parity of 10 symbols each of which consists of one byte (referred to as a C1 parity hereinafter) for error correction of the data. Then, thirteen data frames constitute one sector 52. Therefore, one block is comprised of twelve sectors 52 in this case. At the head of each sector 52 is written a physical sector address 50 of each sector 52 (referred to as a sector address hereinafter). Further, it is noted that a synchronous (Sync) pattern (not shown) is generally added to the head of each frame.
In the column parity 53, twelve bytes in the direction of column constitute one parity (referred to as a C2 parity hereinafter), and the parity is used for correcting an error of the 156-byte data series located upward in an identical column. The above-mentioned 156-byte data and 12-byte parity construct an ECC word in the column direction. FIG. 1 shows a logical format of one block, and the block is physically written continuously in a sequence from the frame located in the uppermost position of the block onto a track of an optical disk in a manner as shown in FIG. 2. Therefore, paying attention to the data series in the direction of column, data are discretely arranged on the disk, and this arrangement is referred to as an interleave.
Thus, conventionally, in both of (a) the data arrangement in the direction of row, i.e., the data series which is not interleaved and (b) the data arrangement in the direction of column, i.e., the data series which is interleaved, the data area 90 in which data is arranged and the parity area 91 in which the parity is arranged have been clearly distinguished from each other.
However, according to the recent trend of increasing the storage capacities and reducing the access times of optical disks, upon reading out data from any optical disk in which the data have been written by the prior art arrangement method, there have been such problems as follows.
Attention is now paid to timings for detecting sector addresses upon continuously reading out information along a track. FIG. 3 shows the timings for the above operation. In this case, the information data is sequentially read out from the frame located in the uppermost position of the block shown in FIG. 1, and therefore, the twelve sector addresses are detected at a predetermined regular time interval. However, since the twelve column parity frames of the column parity 53 are subsequently read out, and therefore, a certain time interval continues for which no sector address is detected continues. Thereafter, the next block is read out, and then, the similar phenomenon occurs repetitively.
Thus, according to the conventional method for arranging the parity of the ECC, the timings for detecting the sector addresses becomes irregular. Therefore, upon retrieving a desired sector address, a complicated control circuit and a complicated calculator circuit are necessary, and this leads to a cause of retarding the time of reading-out. In this case, for example, by providing only the row parity without adding the column parity itself, the timings for detecting the sector addresses can be made regular. However, with only the row parity, the data correcting capability is reduced to impair the reliability of the recorded data.
A first object of the present invention is therefore to provide a data transmission system comprising a data transmitter and a data receiver, said system being capable of regularly transmitting information data in a data area, and regularly receiving the information data arranged regularly in the data area without impairing the reliability of the transmitted data.
A second object of the present invention is to provide a data recording and reproducing apparatus comprising a data recorder and a data reproducer, said apparatus being capable of regularly recording or writing information data in a data area, and regularly reproducing or reading-out the information data arranged regularly in the data area without impairing the reliability of the recorded data.
A third object of the present invention is to provide a recording medium, in which information data can be regularly recorded or written in a data area, and the recorded information data regularly arranged regularly in the data area can be reproduced or read out without impairing the reliability of the recorded data.
A fourth object of the present invention is to provide a data structure for use in a recording medium, in which information data can be regularly recorded or written in a data area, and the recorded information data regularly arranged regularly in the data area can be reproduced or read out without impairing the reliability of the recorded data.
A fifth object of the present invention is to provide a method for arranging a parity of an ECC, by which information data can be regularly recorded or written in a data area, and the recorded information data regularly arranged regularly in the data area can be reproduced or read out without impairing the reliability of the recorded data.
A sixth object of the present invention is to provide a method for transmitting information data, capable of regularly transmitting information data in a data area.
A seventh object of the present invention is to provide a method for receiving information data, capable of regularly receiving information data arranged regularly in the data area without impairing the reliability of the transmitted data.
An eighth object of the present invention is to provide a method for recording information data, capable of regularly recording or writing information data in a data area of a recording medium.
A ninth object of the present invention is to provide a method for reproducing information data, capable of regularly reproducing or reading out information data arranged regularly in the data area of the recording medium without impairing the reliability of the transmitted data.
In order to achieve the above-mentioned objective, according to a first aspect of the present invention, there is provided a data transmission system for transmitting information data with a parity of an error correcting code for correcting an error in the information data, comprising a data transmitter and a data receiver,
wherein said data transmitter comprises:
first storage means for storing information data to be transmitted;
second storage means for storing a parity of an error correcting code;
write control means for writing input information data to be transmitted into said first storage means;
parity generating means for generating a parity to form an error correcting code word of an error correcting code for correcting an error of the information data using a predetermined error correcting coding method in response to the information data stored in said first storage means, and writing the parity into said second storage means;
transmitting means for transmitting the information data stored in said first storage means together with the parity stored in said second storage means; and
read-out control means for controlling said transmitting means to transmit the information data stored in said first storage means and the parity stored in said second storage means so that each data component of the information data obtained by dividing the information data of one data block area into a plurality of data components and each parity component of the parity obtained by dividing the parity of one block area into a plurality of parity components are transmitted at intervals of each sector having a sector address, said sector being defined as an data area obtained by dividing one data block area of a predetermined data amount into a plurality of sectors each having an identical data amount,
wherein data receiver comprises:
receiving means for receiving each data component of the information data and each parity component of the parity which are transmitted at intervals of each sector by said transmitting means;
data extracting means for extracting the information data of one block area by combining a plurality of data components received by said receiving means;
parity extracting means for extracting the parity of one block area by combining a plurality of parity components received by said receiving means; and
error correcting means for correcting an error in the information data of one block area extracted by said data extracting means, using a predetermined error correcting decoding method, based on the parity of one block area extracted by said parity extracting means, and outputting an error-corrected information data.
In the above-mentioned data transmission system, the parity preferably includes a row parity and a column parity, and each sector is comprised of a plurality of frames,
wherein said read-out control means controls said transmitting means to transmit the row parity at the tail of each frame after each data component, and the column parity in the last frame of each sector.
According to a second aspect of the present invention, there is provided a data transmitter for transmitting information data with a parity of an error correcting code for correcting an error in the information data, comprising:
first storage means for storing information data to be transmitted;
second storage means for storing a parity of an error correcting code;
write control means for writing input information data to be transmitted into said first storage means;
parity generating means for generating a parity to form an error correcting code word of an error correcting code for correcting an error of the information data using a predetermined error correcting coding method in response to the information data stored in said first storage means, and writing the parity into said second storage means;
transmitting means for transmitting the information data stored in said first storage means together with the parity stored in said second storage means; and
read-out control means for controlling said transmitting means to transmit the information data stored in said first storage means and the parity stored in said second storage means so that each data component of the information data obtained by dividing the information data of one data block area into a plurality of data components and each parity component of the parity obtained by dividing the parity of one block area into a plurality of parity components are transmitted at intervals of each sector having a sector address, said sector being defined as an data area obtained by dividing one data block area of a predetermined data amount into a plurality of sectors each having an identical data amount.
In the above-mentioned data transmitter, the parity preferably includes a row parity and a column parity, and each sector is comprised of a plurality of frames,
wherein said read-out control means controls said transmitting means to transmit the row parity at the tail of each frame after each data component, and the column parity in the last frame of each sector.
According to a third aspect of the present invention, there is provided a data receiver for receiving information data with a parity of an error correcting code for correcting an error in the information data, comprising:
receiving means for receiving each data component of the information data and each parity component of the parity which are transmitted at intervals of each sector;
data extracting means for extracting the information data of one block area by combining a plurality of data components received by said receiving means;
parity extracting means for extracting the parity of one block area by combining a plurality of parity components received by said receiving means; and
error correcting means for correcting an error in the information data of one block area extracted by said data extracting means, using a predetermined error correcting decoding method, based on the parity of one block area extracted by said parity extracting means, and outputting an error-corrected information data.
According to a fourth aspect of the present invention, there is provided a data recording and reproducing apparatus for recording information data with a parity of an error correcting code for correcting an error in the information data into a recording medium, and reproducing the information data with the parity from said recording medium, comprising a data recorder and a data reproducer,
wherein said data recorder comprises:
first storage means for storing information data to be recorded;
second storage means for storing a parity of an error correcting code;
write control means for writing input information data to be recorded into said first storage means;
parity generating means for generating a parity to form an error correcting code word of an error correcting code for correcting an error of the information data using a predetermined error correcting coding method in response to the information data stored in said first storage means, and writing the parity into said second storage means;
recording means for recording into said recording medium, the information data stored in said first storage means together with the parity stored in said second storage means; and
read-out control means for controlling said recording means to record the information data stored in said first storage means and the parity stored in said second storage means so that each data component of the information data obtained by dividing the information data of one data block area into a plurality of data components and each parity component of the parity obtained by dividing the parity of one block area into a plurality of parity components are recorded at intervals of each sector having a sector address, said sector being defined as an data area obtained by dividing one data block area of a predetermined data amount into a plurality of sectors each having an identical data amount,
wherein data reproducer comprises:
reproducing means for reproducing each data component of the information data and each parity component of the parity which are recorded at intervals of each sector in said recording medium;
data extracting means for extracting the information data of one block area by combining a plurality of data components reproduced by said reproducing means;
parity extracting means for extracting the parity of one block area by combining a plurality of parity components reproduced by said reproducing means; and
error correcting means for correcting an error in the information data of one block area extracted by said data extracting means, using a predetermined error correcting decoding method, based on the parity of one block area extracted by said parity extracting means, and outputting an error-corrected information data.
In the above-mentioned apparatus, the parity preferably includes a row parity and a column parity, and each sector is comprised of a plurality of frames,
wherein said read-out control means controls said recording means to record the row parity at the tail of each frame after each data component, and the column parity in the last frame of each sector.
According to a fifth aspect of the present invention, there is provided a data recorder for recording information data with a parity of an error correcting code for correcting an error in the information data into a recording medium, comprising:
first storage means for storing information data to be recorded;
second storage means for storing a parity of an error correcting code;
write control means for writing input information data to be recorded into said first storage means;
parity generating means for generating a parity to form an error correcting word of an error correcting code for correcting an error of the information data using a predetermined error correcting coding method in response to the information data stored in said first storage means, and writing the parity into said second storage means;
recording means for recording into said recording medium, the information data stored in said first storage means together with the parity stored in said second storage means; and
read-out control means for controlling said recording means to record the information data stored in said first storage means and the parity stored in said second storage means so that each data component of the information data obtained by dividing the information data of one data block area into a plurality of data components and each parity component of the parity obtained by dividing the parity of one block area into a plurality of parity components are recorded at intervals of each sector having a sector address, said sector being defined as an data area obtained by dividing one data block area of a predetermined data amount into a plurality of sectors each having an identical data amount.
In the above-mentioned data recorder, the parity preferably includes a row parity and a column parity, and each sector is comprised of a plurality of frames,
wherein said read-out control means controls said recording means to record the row parity at the tail of each frame after each data component, and the column parity in the last frame of each sector.
According to a sixth aspect of the present invention, there is provided a data reproducer for reproducing information data with a parity of an error correcting code from a recording medium, comprising:
reproducing means for reproducing each data component of the information data and each parity component of the parity which are recorded at intervals of each sector in said recording medium;
data extracting means for extracting the information data of one block area by combining a plurality of data components reproduced by said reproducing means;
parity extracting means for extracting the parity of one block area by combining a plurality of parity components reproduced by said reproducing means; and
error correcting means for correcting an error in the information data of one block area extracted by said data extracting means, using a predetermined error correcting decoding method, based on the parity of one block area extracted by said parity extracting means, and outputting an error-corrected information data.
According to a seventh aspect of the present invention, there is provided a recording medium having a data structure of information data and a parity of an error correcting code for correcting an error in the information data, said recording medium being usable by a data reproducer,
said recording medium comprising:
data reproducer readable information data; and
data reproducer readable parity of an error correcting code,
wherein each data component of the information data obtained by dividing the information data of one data block area into a plurality of data components and each parity component of the parity obtained by dividing the parity of one block area into a plurality of parity components are recorded at intervals of each sector having a sector address, said sector being defined as an data area obtained by dividing one data block area of a predetermined data amount into a plurality of sectors each having an identical data amount.
In the above-mentioned recording medium, the parity preferably includes a row parity and a column parity, and each sector is comprised of a plurality of frames,
wherein the row parity is recorded at the tail of each frame after each data component, and the column parity is recorded in the last frame of each sector.
According to an eighth aspect of the present invention, there is provided a data structure for use in a recording medium having information data and a parity of an error correcting code for correcting an error in the information data, said recording medium being usable by a data reproducer,
said data structure comprising:
data reproducer readable information data; and
data reproducer readable parity of an error correcting code,
wherein each data component of the information data obtained by dividing the information data of one data block area into a plurality of data components and each parity component of the parity obtained by dividing the parity of one block area into a plurality of parity components are recorded at intervals of each sector having a sector address, said sector being defined as an data area obtained by dividing one data block area of a predetermined data amount into a plurality of sectors each having an identical data amount.
In the above-mentioned data structure, the parity preferably includes a row parity and a column parity, and each sector is comprised of a plurality of frames,
wherein the row parity is recorded at the tail of each frame after each data component, and the column parity is recorded in the last frame of each sector.
According to a ninth aspect of the present invention, there is provided a method for arranging a parity of an error correcting code for correcting an error in the information data, in a recording medium, including the following step of:
arranging the information data and the parity so that each data component of the information data obtained by dividing the information data of one data block area into a plurality of data components and each parity component of the parity obtained by dividing the parity of one block area into a plurality of parity components are recorded at intervals of each sector having a sector address, said sector being defined as an data area obtained by dividing one data block area of a predetermined data amount into a plurality of sectors each having an identical data amount.
In the above-mentioned method, the parity preferably includes a row parity and a column parity, and each sector is comprised of a plurality of frames,
wherein said arranging step includes the step of arranging the row parity at the tail of each frame after each data component, and the column parity in the last frame of each sector.
According to a tenth aspect of the present invention, there is provided a method for transmitting information data with a parity of an error correcting code for correcting an error in the information data, including the following steps of:
writing input information data to be transmitted into first storage means;
generating a parity to form an error correcting code word of an error correcting code for correcting an error of the information data using a predetermined error correcting coding method in response to the information data stored in said first storage means, and writing the parity into said second storage means;
transmitting the information data stored in said first storage means together with the parity stored in said second storage means; and
controlling to transmit the information data stored in said first storage means and the parity stored in said second storage means so that each data component of the information data obtained by dividing the information data of one data block area into a plurality of data components and each parity component of the parity obtained by dividing the parity of one block area into a plurality of parity components are transmitted at intervals of each sector having a sector address, said sector being defined as an data area obtained by dividing one data block area of a predetermined data amount into a plurality of sectors each having an identical data amount.
In the above-mentioned method, the parity preferably includes a row parity and a column parity, and each sector is comprised of a plurality of frames,
wherein said controlling step includes the step of controlling to transmit the row parity at the tail of each frame after each data component, and the column parity in the last frame of each sector.
According to an eleventh aspect of the present invention, there is provided a method for receiving information data with a parity of an error correcting code for correcting an error in the information data, including the following steps of:
receiving each data component of the information data and each parity component of the parity which are transmitted at intervals of each sector;
extracting the information data of one block area by combining a plurality of received data components;
extracting the parity of one block area by combining a plurality of received parity components; and
correcting an error in the information data of one block area extracted, using a predetermined error correcting decoding method, based on the parity of one block area extracted, and outputting an error-corrected information data.
According to a twelfth aspect of the present invention, there is provided a method for recording information data with a parity of an error correcting code for correcting an error in the information data into a recording medium, including the following steps of:
writing input information data to be recorded into first storage means;
generating a parity to form an error correcting code word of an error correcting code for correcting an error of the information data using a predetermined error correcting coding method in response to the information data stored in said first storage means, and writing the parity into second storage means;
recording into said recording medium, the information data stored in said first storage means together with the parity stored in said second storage means; and
controlling to record the information data stored in said first storage means and the parity stored in said second storage means so that each data component of the information data obtained by dividing the information data of one data block area into a plurality of data components and each parity component of the parity obtained by dividing the parity of one block area into a plurality of parity components are recorded at intervals of each sector having a sector address, said sector being defined as an data area obtained by dividing one data block area of a predetermined data amount into a plurality of sectors each having an identical data amount.
In the above-mentioned method, the parity preferably includes a row parity and a column parity, and each sector is comprised of a plurality of frames,
wherein said controlling step includes the step of controlling to record the row parity at the tail of each frame after each data component, and the column parity in the last frame of each sector.
According to a thirteenth aspect of the present invention, there is provided a method for reproducing information data with a parity of an error correcting code from a recording medium, including the following steps of:
reproducing each data component of the information data is and each parity component of the parity which are recorded at intervals of each sector in said recording medium;
extracting the information data of one block area by combining a plurality of data components reproduced;
extracting the parity of one block area by combining a plurality of parity components reproduced; and
correcting an error in the information data of one block area extracted, using a predetermined error correcting decoding method, based on the parity of one block area extracted, and outputting an error-corrected information data.
According to the present invention, a parity is not recorded in a bunched continuous area but recorded dispersedly in each sectors of the areas in which the data to be corrected is recorded. Therefore, the information data arranged regularly in the data area is regularly read out, thereby producing such an advantageous effect that the data reproducing or read-out apparatus is allowed to be simplified and improved for higher operation speed.
Further, according to the present invention, the parity is not solely transmitted continuously but transmitted in such a manner that it is dispersedly mixed with the data to be corrected. The above arrangement produces such an advantageous effect that the information data arranged regularly in the data area can be transmitted at a predetermined constant time interval.
Furthermore, according to the present invention, when interleaved symbol data or ECC block data is received, the data series and the parity are reproduced from the symbol data or ECC block data, so that the error generated in the data series is corrected. Therefore, when the parity is dispersedly transmitted, the data series and the parity are easily recognized, thereby producing such an advantageous effect that the error generated in the data series is corrected.